The ring airfoil projectile (RAP) has unique aerodynamic characteristics: high lift, and low drag. By spinning the ring airfoil at launch, gyroscopic stability results, and relatively flat trajectories with extended range are achievable.
The initial application of the ring airfoil in a self-contained munition appeared in the early 1970's (see U.S. Pat. No. 3,877,383 to Flatau). This early configuration was designed as high-explosive fragmentation projectile. Shortly thereafter, several designs appeared for use as a less-than-lethal (LTL) projectile by making the ring airfoil body of a rubber-like material and incorporating cavities to contain chemical-incapacitation agents (see U.S. Pat. Nos. 3,898,932, 3,951,070, and 4,190,476 to Flatau). Upon target impact, the LTL RAP dispersed its load of agent on and about the target.
To date, all of the launchers associated with LTL ring airfoil projectile have been single-shot devices (see U.S. Pat. No. 4,154,012 to Miller and U.S. Pat. No. 5,970,970 to Vanek). Hence, the design of the subject launcher as semi-automatic or repeating mechanism is a progressive step in the technology of launching spinning ring airfoil projectiles, particularly for LTL use.